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The species found in a particular place (“species assemblages”) differ from those found in other places, and figuring out why this is so has occupied the minds of ecologists since the mid-20th century. Currently two theories dominate: the niche theory, and the neutral theory. The niche theory holds that species assemblages result from species migrating into a particular place, and then either thriving or leaving based on how good of a match they are to the habitat and other living organisms (the “niche”) in that place.

Schistosomiasis (also known as billharzia) is a parasitic flatworm that infects a quarter of a billion people worldwide, mostly in tropical countries. If left untreated, it causes chronic pain and diseases of the liver and kidney, and kills up to 200,000 people annually. In recent years, control of the disease has focused on mass-treating humans with a drug called praziquantel, instead of reducing the prevalence of snails that are a required part of the parasite’s life cycle.

By Ben Miller, SAFS student
When you first arrive at the community of Kampong Phluk, your neck cranes up bamboo stilts to meet the chatter of families in houses high above. From the top of what guidebooks call “bamboo skyscrapers,” locals gaze over the tops of submerged trees, a glittering, island Buddhist temple, and clusters of floating fishing villages in the distance.

Salmon are capable of using the Earth’s magnetic field as a part of their built-in navigating skills to home back to their streams of birth. Now it has been discovered that young salmon emerging from the gravel also use the Earth’s magnetic field to figure out which way is up. Salmon eggs are laid in gravel nests, and the young salmon remain in the gravel until all of the attached yolk reserves are finished, then they emerge to live out in the open water.

Satellite tracking devices on beluga whales in the Arctic show how they reacted to far lower sea ice concentrations in recent years. Instead of shifting where they feed, as might have been expected, beluga whales continued to feed in similar (but now largely ice-free) places. However, where dive data were available, their dives were significantly longer and deeper than in years with higher ice concentrations.

Combining data from glaciers with tracking devices on narwhals, reveals that these elusive marine mammals prefer glaciers that calve infrequently over active calving glaciers. The research, to be presented by SAFS professor Kristin Laidre at the Ocean Sciences Meeting next week, shows narwhals congregating at the outlets of serene glaciers in Greenland’s Melville Bay. Prof. Laidre speculates that the cold fresh water melting off the glacier may stun fish, making them easy prey for the hunting narwhals, while active glaciers produce more silt-filled waters that are harder to hunt in.

The intent of ecosystem-based fisheries management is to move beyond managing each species separately, and to also consider interactions with other species and ecosystem functioning, as well as human benefits such as food, revenue and recreation. A new paper shows that, in practice, people have very different opinions about which management actions could be classed as ecosystem-based. Furthermore, it is highly unlikely that any particular fishery would be able to meet all of the items on a checklist of possible ecosystem-based actions.

Nearly all fisheries management is based on assessing one species at a time, ignoring any interactions with other species. Many have claimed that including these interactions will improve management and lead to greater fisheries profits. A new paper tests whether precise information on species interactions improves economic performance in fisheries. Somewhat reassuringly, economic value was not markedly lower if managers assumed that an incorrect type of interaction was true.

Millions of tons of plastics enter the ocean each year, and many of these end up entangling on coral reefs. Microbes that live on the plastic can then cause coral diseases. A new study appearing in Science today examined more than 100,000 individual corals, finding that only 4% of corals have disease when they are plastic free, but a staggering 89% of corals that are in contact with plastics are diseased.

Not all piranhas eat in the feeding frenzies that Hollywood is so fond of depicting. Instead, some species remove and eat just a few scales from their prey. As described in UW News, some of these scale-eaters ram into their unsuspecting prey, while others open their mouths to extraordinary dimensions and use specialized teeth to pry off scales. The wide variety of approaches is captured in a new paper that placed these fish in CT scanners, as part of the Scan All Fish program led by SAFS professor Adam Summers.